Duodenal microbiota makes an important impact in functional dyspepsia

Small intestinal microbiota: from taxonomic composition to metabolism

The small intestinal microbiota (SIM) is essential for gastrointestinal health, influencing digestion, immune modulation, and nutrient metabolism. Unlike the colonic microbiota, the SIM has been poorly characterized due to sampling challenges and ethical considerations. Current evidence suggests that the SIM consists of five core genera and additional segment-specific taxa. These bacteria closely interact with the human host, regulating nutrient absorption and metabolism. Recent work suggests the presence of two forms of small intestinal bacterial overgrowth, one dominated by oral bacteria (SIOBO) and a second dominated by coliform bacteria. Less invasive sampling techniques, omics approaches, and mechanistic studies will allow a more comprehensive understanding of the SIM, paving the way for interventions engineering the SIM towards better health.

Pharmacokinetics and tissue distribution of four major bioactive components of Cynanchum auriculatum extract: a UPLC-MS/MS study in normal and functional dyspepsia rats

Introduction: Cynanchum auriculatum (CA) is usually used to treat digestive disorders, such as anorexia, enteritis, dysentery, and indigestion. Functional dyspepsia (FD) is characterized by a group of symptoms associated with the gastroduodenal region. Recent pharmacological studies have demonstrated the efficacy of CA for treating FD. However, the pharmacokinetics (PK) and tissue distribution of CA in physiological and FD states is still unclear. The present study aimed to clarify the differences in PK parameters and tissue distribution of the four major active components of CA (baishouwu benzophenone, deacylmet-aplexigenin, qingyangshengenin, and syringic acid) under both physiological and FD states. Methods: For this, normal and FD rats were orally administered 10 mg/kg CA extract. Then, plasma and tissue (heart, liver, spleen, lung, kidney, brain, stomach, and small intestine) samples were obtained. The four active components of CA in rat plasma and tissues were quantified by developing and validating a fast and reliable ultra-high-performance liquid chromatography-mass spectrometry method. Results: The area under the plasma concentration-time curve from time zero to time t (AUC0-t) of baishouwu benzophenone was significantly lower in the FD group than in the normal group (p < 0.01). The FD group had significantly lower (p < 0.001) apparent volume of distribution and plasma clearance of qing-yangshengenin and significantly higher (p < 0.05) AUC0-t of deacylmetaplexigenin and qingyangshengenin. The four active components were rapidly distributed into various tissues, and the main target organs of CA activity were the stomach and small intestine. In addition, baishouwu benzophenone, deacylmetaplexigenin, and qingyangshengenin could cross the blood-brain barrier, indicating that the brain may be another target organ in the treatment of FD. Discussion: These results indicate that the pathological state of FD alters the PK behavior and tissue distribution characteristics of baishouwu benzophenone, deacylmetaplexigenin, qingyangshengenin, and syringic acid in the CA extract, providing an experimental basis for the role of CA in FD treatment.

Progress in understanding of relationship between duodenal mucosal microecology and hepatitis B virus related acute-on-chronic liver failure

According to statistics, the rate of hepatitis B virus (HBV) infection is still high in China, and the mortality of acute-on-chronic liver failure (ACLF) is also high. In recent years, studies on the fecal flora of patients with HBV related ACLF have found that intestinal microecology affects the occurrence, development, and prognosis of HBV related ACLF. However, fecal flora cannot completely replace the whole intestinal microecology, and duodenal mucosal microecology may be a new research direction. This review discusses the influence of duodenal mucosal flora on the clinical outcome of HBV-ACLF with regard to mechanism, physiology, and anatomical characteristics.

Functional Gastrointestinal Disorders with Psychiatric Symptoms: Involvement of the Microbiome-Gut-Brain Axis in the Pathophysiology and Case Management

Functional Gastrointestinal Disorders have been an important cause of poor life quality in affected populations. The unclear etiology and pathophysiological mechanism alter the clinical evolution of the patient. Although a strong connection with psychological stress has been observed, it was not until recently that the gut-brain axis involvement has been revealed. Furthermore, the current literature not only promotes the gut-brain axis modulation as a therapeutical target for functional digestive disorders but also states that the gut microbiome has a main role in this bi-directional mechanism. Psychiatric symptoms are currently recognized as an equally important aspect of the clinical manifestation and modulation of both the digestive and central nervous systems and could be the best approach in restoring the balance. As such, this article proposes a detailed description of the physiology of the microbiome-gut-brain axis, the pathophysiology of the functional gastrointestinal disorders with psychiatric symptoms and current perspectives for therapeutical management, as revealed by the latest studies in the scientific literature.

Effects of Pb-, Cd-resistant bacterium Pantoea sp. on growth, heavy metal uptake and bacterial communities in oligotrophic growth substrates of Lolium multiflorum Lam

Phosphate-solubilizing bacteria (PSB) can accelerate phytoremediation, especially in those fertilized soils. However, PSB function in oligotrophic growth substrates remains poorly studied. In this study, we isolated lead (Pb)- and cadmium (Cd)-resistant PSB from contaminated sandy soil at an abandoned lubricant plant. The isolated Pantoea sp. PP4 (PP4 hereafter) can produce organic acid and IAA (Indole-3-acetic acid) and dissolve up to 238 mg/L of inorganic phosphate Ca2(PO4)3, exhibiting biosorption capability for Pb and bioprecipitation for Pb and Cd. In the sand pot experiment, inoculation of PP4 increased the accumulation of Pb and Cd in Lolium multiflorum Lam. by 28.9% and 95.5%, respectively, and increased the available phosphorous in oligotrophic river sand by 30.8% (P < 0.05). Meanwhile, the growth of Lolium multiflorum Lam. was also stimulated, resulting in 89.2%, 57.1%, 184.6%, and 28.5% increase in fresh weight, dry weight, root length, and shoot length, respectively. NMDS analysis showed that the bacterial communities in river sand were more clustered after inoculation with PP4. These results indicated that the application of Pantoea sp. PP4 can facilitate the phytoremediation of Pb and Cd in oligotrophic growth substrates, forming a convergent bacterial community. Our findings highlighted the importance of identifying ideal PSB to improve phytoremediation efficiency in oligotrophic environments.